INTRODUCTION: Triage to the intensive care unit (ICU) after elective total hip arthroplasty (THA) proves a complex medical and resource decision point. We sought to prospectively test our model of pre-operative risk stratification at a tertiary, high-volume arthroplasty center.METHODS: A total of 175 consecutive patients were triaged to either an ICU bed or routine post-operative floor according to established ICU admission criteria. Threshold for ICU triage was ≥2 risk factors: age >75 years, revision surgery, creatinine clearance <60mL/min or BMI>35. These factors were established from a prior retrospective study of 1,259 consecutive THA patients. Primary endpoints were a reduction in unplanned admission to the ICU, as well as mortality and major complications. A pre-study power analysis demonstrated adequate patient numbers. Costs per patient were calculated.RESULTS: All patients were prospectively triaged and followed during the study period. After implementation of our triage model, the rate of unplanned ICU admissions dropped from 7.1% to 2.2% (p=0.013). In an intent-to-treat analysis, the unplanned admission rate was 0.6% (p<0.001). Likewise, the major complication rate fell from 12.5% to 2% with intervention. There was only a modest (11.4% from 7.1%) total increase in number of ICU admits. The as-treated odds of unplanned admission pre- versus post-intervention was 3.2 (1.2, 10.6).DISCUSSION AND CONCLUSION: Pre-operative triage to the ICU according to selected risk factors affects a reduction in post-operative unplanned ICU admissions and major complications after elective total hip arthroplasty.